Hi Muzz.
Here to be legal you need a tow line , sounding device ( whistle ) pump
or bailing device, padde ( just One ) PFD ( BA or Boyancy Aid there ).
I carry flares, marine VHF, Cell phone when it works (coverage) some
emergency food, flash lighs, compasses (2) emergency blankets, a small
first aid kit , matches and waxed fire starter, a candle or two and an
emergency change of clothes.
Temperatures here are sub zero and we don't have the Royal life boat
service you have . Out military is not that close when you need them
either.
I suspect if you dress for conditions and have the paddle float, tow
rope , pump, a spare paddle and a meens to stayb or get warm you should
be fine.
Training is the answer of course. Its cheaper and less painfull to
learn from someone elses errors.
Alex